vCenter Server: Installable versus Appliance. Often when designing an infrastructure there is a choice to be made between the two options. Go for the easy and fast to deploy appliance or go for the scalable and flexible installation. Where with the previous version of ESX before version 5.5 the vCenter Server appliance was limited, when using the embedded database, to environments of up to 5 ESXi hosts and 50 virtual machines. Now that the maximum is raised to 100 supported ESXi hosts and 3000 supported VMs you have a new viable choice to go for the appliance with the internal database. New in vSphere 5.5 is support for clustering of the vCenter Server Database, this can be a viable option because the vCenter server heavily depends on the database that is used to store configuration and statisticals.

The following is a comparison between the Appliance and the Installable version of vCenter Server:

vCenter Server

Appliance

Installable

Running on

A pre-configured SUSE Enterprise Linux based virtual appliance

The installable version is a Windows application supported on Windows Server 2008R2 64-bit and Windows Server 2012.*Service pack information should be verified before installation in either a virtual or physical machine

Package

OVF template

ISO file

Server Virtual or Physical

Virtual

Virtual or Physical

Database

Database internal

vPostgreSQL database

Microsoft SQL Express database

Supports #ESXi host

100

5

Supports #VM’s

3000

50

Larger environment?

Use an external database

Use an external database

External Database supported

Oracle

Microsoft SQL or Oracle

vCenter Server Options

Auto Deploy

Pre-installed

Separate installation

Syslog Collector

Pre-installed

Separate installation

ESXi Dump Collector

Pre-installed

Separate installation

vSphere Web Client

Pre-installed

As part of vCenter Install

Single Sign-On

Pre-installed

As part of vCenter Install

Scripting & Automation of the DC

vSphere CLI

Cannot be installed

Separate installation

PowerCLI

Cannot be installed

Separate installation

Network

IPv4 or IPv6 support

Supports IPv4 Only

Supports IPv4 and IPv6

vCenter Update Manager

Cannot be installed inside

Can be installed on the vCenter Server

Linked Mode

Not compatible

Compatible

vCenter Heartbeat

Not compatible

Compatible

Note: the Syslog Collector and ESXi Dump collector must be registered as a plug-in in vCenter Server.

vCenter Server

vCenter Server is comprised of a number of interlinked components and interfaces to other services and infrastructure. I will describe each of the key components and their role in vCenter below.

vCenter Single Sign-On

vCenter Inventory Service

vCenter Server (Core)

Web Client

1. vCenter Single Sign-On

Offers administrators a deeper level of authentication services that enable VMware solutions to trust each other. SSO allows VMware solutions to utilize multiple directory services and is no longer limited to Microsoft Active Directory. It simplifies the management of multi-site and multi-installation environments by allowing users to move seamlessly between multiple environments without re-authentication. A SSO server can be installed separately and can support multiple vCenter installations. The SSO server must be able to communicate with your identity sources such as Open LDAP, Microsoft Active Directory or a Local Operating System.

2. vCenter Inventory Service

Optimizes client server communications by reducing the number of client requests on vCenter Server. It is now a separate independent component that can be off-loaded to a separate server. (Installable version only!) This can be used to reduce traffic and improve client response times. It also enables users to create and add inventory object-level tags.

These are then used to organize and provide quicker retrieval when performing inventory searches. The inventory service must be able to communicate with the SSO server, the vCenter Server and the client.

3. vCenter Core

Core Services

Are the basic management services for a virtual Data Center. These include virtual machine provisioning; statistics and logging; host host and virtual machine configuration; alarms and event management; and task scheduling. The vCenter Server must be able to communicate with the ESXi hosts and must be accessible to any systems that require access to the API.

Distributed services

Are solutions that extend VMware vSphere capabilities beyond the single physical server. These solutions are DRS, HA, vMotion. They are configured and managed centrally from vCenter Server.

vCenter API

Provides access to the vSphere management components. These are the objects that you can use to manage, monitor and control lifecycle operations of virtual machines and other parts of the virtual infrastructure. (Networks, Datastores, Datacenter, etc.)

The vCenter API provides the interface to vCenter that is used by the vCenter Clients, third party applications, plug-ins and VMware applications such as vCAC. It is available for administrators, developers and partners to integrate and automate solutions.

4. Web Client

Provides a rich application experience in a wide variety of web browsers. This surpasses the functionality of the trusted VMware vSphere Client (the VI or Desktop Client) running on Windows.

Can be installed on the vCenter Server along with other vCenter Server components or it can be installed on a Windows Management server or Windows desktop. The Web Client is accessed via a Web browser that connects to the Web Client Server. The web clients is now the primary management client, because from vSphere 5.5 all of the new vSphere features are only available when using the Web Client interface. (New vSphere 5.5 features include: 62TB VMDK, vFlash Configuration)

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Edwin Weijdema

Edwin Weijdema is a Solutions Architect at Veeam for the Benelux & Nordics region and has over 20 years of experience designing, implementing, and managing data center technologies for large companies. His areas of expertise include virtualization, networking, and storage solutions. He knows what it takes to add business value to partners and customers. He is a veteran vExpert, Cisco Champion 2015 and holds several other certifications.